Repairing Silicone Tear

[Flipper]

I have a healthy, well seasoned tank with a small section of silicone slightly torn.  The tear is 4 inches below the water line.  I just can't start over with a new tank; I've worked so hard.  My LFS (not a big box store, but employees who know aquatics) told me to remove enough water to get below the tear, dry area, repair with silicone and let it sit for 48 hrs before filling back up.  I am concerned about my HOB filter losing the good BB.  Was told to sit filter on bottom of tank during the repair.

I just want a second opinion on this plan.

[Guppysnail]

Some hob motors are not meant to be submerged. I would sit the media in the tank after rinsing in tank water. I would run a seasoned sponge filter in it. 
 

The repairing I know nothing about. 

[lefty o]

my opinion, that tear just looks like some of the smear out. if its not actually torn into the corner seam itself, i would not mess with it. especially since new silicone does not like to adhere to old dry silicone.

[nabokovfan87]

On 12/7/2023 at 2:48 PM, Flipper said:

I am concerned about my HOB filter losing the good BB.  Was told to sit filter on bottom of tank during the repair.

you can just use an airstone, drop the waterline, and drop all your ceramic media into the tank for a few days.  It should keep everything going.

That being said, it's incredibly difficult to repair a seam line that.  The silicone prep you need to do in order to get the bond to hold over time is going to be something that isn't as simple as adding some to the portion that was damaged.  The way the glass tanks are bonded there is two beads of silicone.  The first is the ones that is used to seal one pane of glass to the next.  This is the portion you see when the glass is placed against one another to form the cube.  The second seam is the internal one that is along all of the edges to try to fully waterproof the tank. 

The portion that is damaged is that inner seal and it looks like what you would want to do is just keep and eye on it and make sure you don't see things progress.  Take photos and keep a record for yourself to look back at.  It's a weak point, but not might actually be damage to the seal itself.  Let me elaborate...



This gives you an idea of how to repair a seam and what happens when you try to do layers of silicone as opposed to proper bonding of the silicone to the glass.
 

The fish corner ran into a similar issue where they had a leak... Ohio fish rescue same thing.... and they did a similar thing of trying to clean it, prep it, and then add more silicone, but ultimately it is very difficult to prep it properly and get the silicone to bond.  You might get bubbles, you might have it just peel off after a short time, there's a lot of ways where it may not do anything if you just add some to that area.

[Tlindsey]

On 12/7/2023 at 5:48 PM, Flipper said:

small section of silicone slightly torn.  

@Flipper I wouldn't worry about it. Looks like you have good seal with silicone inside the aquarium and between both panels of glass. It would have been leaking if it was a issue imo. If you decide to do that I would just smear enough silicone just to cover the missing section.

Keep in mind the silicone must cure completely prior to filling back up. Also fumes from silicone may possibly harm your fish.

 

 

Edited December 8, 2023 by Tlindsey

[Galabar]

On 12/7/2023 at 4:16 PM, lefty o said:

my opinion, that tear just looks like some of the smear out. if its not actually torn into the corner seam itself, i would not mess with it. especially since new silicone does not like to adhere to old dry silicone.

I agree.  It probably doesn't need to be repaired.

[Matt B]

I would agree with others on this. I wouldn't worry about it. I have a small 3.7 gal tank that has several places on the bottom and sides like that and it has never leaked. 

[DaveO]

That doesn't look bad at all. If it's not leaking, leave it alone.

[Andy's Fish Den]

As others have said, I would leave it alone. I have several older tanks in my fish room that have silicone that looks like that and they are all fine. To repair correctly would entail draining the tank down, removing all the silicone well and putting new down. New silicone won't bond to old, so you have to remove all the old. I wouldn't worry about it unless it starts to leak. 

[Flipper]

Thank you all SO much.  😃

I wish I'd been a co-op member when I started my hobby 5 years ago.  You guys could have helped me in my struggles, but I'm a member now and feel fortunate.  I could not find a better bunch of enthusiasts, anywhere.  You all ROCK! 

[Flipper]

On 12/7/2023 at 6:20 PM, nabokovfan87 said:

The way the glass tanks are bonded there is two beads of silicone.

I definitely did not know this fact, though when I think of it, sounds like a much safer way to build aquarium corners, 2 layers, not just 1.  Good to know.  😉

I'm not going to fix my tear, just baby it.  Thanks

[tolstoy21]

On 12/7/2023 at 7:16 PM, lefty o said:

my opinion, that tear just looks like some of the smear out. if its not actually torn into the corner seam itself, i would not mess with it. especially since new silicone does not like to adhere to old dry silicone.

Agree. It doesn't look serious enough to cause a leak. As @lefty o said, it just looks like the defect is in the area where the silicon is feathered out to make the seam look neat (the smear happens when the silicon is pushed into into the seam with either a finger or tool). 

That defect is of no structural concern. If it's not leaking now, I doubt it will leak later.  Silicon has an insanely strong bond to glass.

Edited December 8, 2023 by tolstoy21

[Galabar]

Here's a picture of a glass tank from Glass Cages (silicone is only between the glass, with no fan out):

That is similar to most of the rimless tanks that you'll see, which seems to point to the "fan out" of silicone being unnecessary.

If you watch some build videos, they lay down a layer of tape, which is used to remove the fan out and only leave the above.

 

Edited December 9, 2023 by Galabar

[Flipper]

I feel so much better, now.  I kept picturing 20 gallons of water leaking onto my carpet.  I'll sleep easy tonight.  😄

[Flipper]

On 12/8/2023 at 8:41 PM, Galabar said:

watch some build videos

Very informative video, thanks 😊